Caster having an inclined axis



Oct. .19; 1937. GEYER 2,096,239

CASV'IER gums n fINcLmBD Axrs Filed May 2, 1935 PLAN! ar noi-n'rlou o'F conllnc'rmo PORTION 1 er nous! PLINE or Mignon OF ROLLER no" R: rrnuu 51 my D, Sayer or cou'rnu'mo Milan i 4H INVENTORI v I Patented o... 19, 1937 PATENT) OFFICE CASTER HAVING AN INCLINED AXIS- Harvey D. Geyer, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application- May 2, 1995, Serial No. 19,353

' 5 Claims.

This invention relates to an improved form of swivel caster designed to be used on thefloov legs of refrigerators, stoves, tables, beds, desks, chairs, etc.

An object of this invention is to provide a caster that very easily swivels to its following position and so prevents the caster roller from being slid sidewise over the floor, thus preventingmarring of the floor.

A more specific object is to provide a caster having its roller rotatably mounted upon a bearing whose axis is downwardly inclined towards the floor so as to cause said roller to rotate in a plane extending at an angle to the floor. This feature has various important advantages, as follows: (1) it causes the caster roller to more easily orient itself to the proper position -to carry its load in the desired direction; (2) it permits a very simple and eficient form of sealed-end bearing for the caster roller having a single hardened steel ball for carrying the thrust load; (3) the sealed end of the roller bearing is adjacent the floor while the non-sealed end thereof is turned upward away from the floor, which substantially eliminates the tendency of the roller to pick up threads or hair from the floor and wind it around the projecting end of the roller shaft; (4) the downwardly inclined bearing recess in the rollerserves as an oil-retaining reservoir from which the lubricating oil supplied thereto cannot leakdue to the sealed end thereof, thus greatly facilitating the proper lubrication of the caster roller bearing.

Another advantage of the caster roller of this invention is the ease with which it can be efli-- ciently molded from. rubber or other suitable moldable material, due to the fact that one end thereof is entirely closed or sealed and hence a simpler form of mold may be used for molding same.

Further objects and invention willbe apparent from the following description, reference :being had to the accompanya ing drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is an elevation of the caster 'of this invention apart from the supported leg into which the'u pright shankv is rotatably mounted.

Fig. 2 is a section taken on'line 2-2 of Fig. 1.

Figs. 3 and 4 illustrate a modified form of the invention.

Fig. 3 is an elevation similar to Fig.' 1.

Fig. 4 is a section taken on line 4-4 of Fig. 3.

advantages of the present I inclined pivot portion I 2 which serves as the shaft for the caster roller I5. Caster roller I5 is provided with a molded-in cylindrical bearing bushing I6 which fits upon pivot portion I2 and has a closed end I1 which supports the end thrust of the shaft portion I2 due to the inclination thereof. This design permits the use of the very simple and efficient ball thrust bearing illustrated in Fig. 2. Preferably the end of pivot portion I2 is recessed to provide a suitable ball Iseat I3, and a hardened steel'ball I I is retained centrally located by seat I3" and bears upon the hardened closed end I! of the metal bushing insert I6. In the form of the invention illustrated in Figs. 1 and 2, it will be seen that about half of the total weight supported by the'caster is taken by the ball thrust bearing, and the other half is taken by the plain, bearingofthe cylindrical portion of insert I6 upon the shaft portion I2. This provides for a very easy rotation of the roller I5 upon its support and reduced wear of the bearing surfaces.

When roller I5 is molded of hard or semi-hard rubber, bakelite, or other moldable material, the metal insert bushing I6 is set within the mold cavity and held properly located therein by a fixed locating pin which fits snuglywithin bushing I6 which at this time does not have its open end turned inwardly as appears in Fig. 2. The substantially hemi-spherical roller molded to the form shown in Fig. 2 and is bonded to the insert I6 during molding.- The molded roller I5 may thenbe simply slipped over the portion I2 and be permanently assembled thereupon by turning or spinning the projecting metal lip I8 over the shoulder I9 on the shaft I2, as shown in Fig. 2., This prevents the roller I5 from slipping from the end of shaft I2 whenever the casteris raisedfrom the door. Preferablyza dirt and dust cover 20is provided for the upper I or non-sealed end of the bearing. Cover 20 is preferably molded to the shape shown in Fig, 2'

from a graphite-bearing soft rubber compound,

' molded roller I5. Cover 20 of course turns with I so the roller l5 and has a snug'flt upon the metal shaft. ,-A desired amount of lubricating oil or grease is put into thebearing before or after the roller is assembled upon the shaft l2, but prior to the assembling of cover 20 thereupon.

This lubricant cannot leak by gravity or be pressed out of the lower sealed end of the bearing and so will give perfect lubrication for both the thrust bearing and plain bearing for very lone periods. In operation, it will be noted that this caster swivels very easily about the axis of the upright portion I I due to the fact'that the hemi-spherical roller l5 acts somewhat after the manner of a large ball bearing rolling upon the floor in any desired direction of movement. When the direction of movement is that of arrow A" in Fig. 1,

the new resistance (indicated by arrow B in Fig. 1) causes-the roller to rotate, and the floorcontacting portion of the roller moves inthe plane (see Fig. 2) which lies at-an angle to the vertical plane of the direction of movement. The form of the invention shown in Figs. 3 and 4 differs from that of Figs. land 2, mainly in that the molded roller I5. is not continued in heml-spherical form around the sealed end ll" of the metal bearing insert i6 andthus the roller l5"appears morelike an ordinarycaster roller. Also the angle of inclination of the axis of bearing portion I! of the shaft is less than in the above form .and hence there is less load on the end thrust bearing i4, ll. Preferably the tread curvature of the roller I5 is parti-spherical having its center of curvature on the axis of the shaft bearing portion l2. This form functions similarly to that'of Figs. 1 and 2, as fully described above.

' While the embodiment of the present invention as herein disclosed, constitutes a preferred form,- it is to be understood that other forms might be adopted, all coming within the scope -pivot portion and roller.

floor, said roller having a thrust bearing having one axially'located'bail contacting'the lower end of said pivot portion.

'2. A caster comprising: an upright shank portion having a laterally oflset roller pivot portion, said pivot portion being downwardly inclined towards its end, and a caster rollermounted upon said inclined pivot portion so as to rotate in a plane extending at an angle to the supporting floor, said roller having a downwardly'inclined closed-bottom bearing bushing bearing directlyupon said pivot portion and serving as an oilretaining recess for said bearing.

3. A caster comprising: an upright shank portion having a laterally oflset roller pivot portion, said pivot portion being downwardly inclined towards its end, and a caster roller mounted upon said inclinedpivot portion so as to rotate in a plane extending at an angle to the supporting floor, the lower end of said pivot portion having an axial ball recess; a single axially located bearing ball located in said recess and contacting the bottom of the bearing recess in said roller and serving as a thrust bearing between said inclined 4. A caster; comprising: an upright shank portion having a laterally oflfset roller pivot portion, said pivot portion being downwardly inclined towards its end, a caster roller mounted upon said inclined pivot portion so. as to rotate in a plane extending at an angle to the supporting floor,

5 tfiing the lower end'of said pivot portion, and said roller having an inclined closed-bottom bearing bushing bearing directly upon said pivotportion and serving as an oil-retainer for both 7 the axial and thrust bearings.

roller having a single ball thrust bearing con- 5. A caster comprising: an upright shank por- I ing shoulder-thereon adjacent its upper end, and

a caster roller mounted upon said inclined pivot I portion so as to rotate in a plane extending at an angle to the supporting floor, said roller having a closed-bottom metal cup serving as a bearing 

